Question

a) What happens to the work done when the displacement of a body is at right angles to the direction of force acting on it? Explain your answer.

b) A force of 50N acts on a body and moves it a distance of 4m on a horizontal surface. Calculate the work done if the direction of force is at an angle of 60 degree to the horizontal surface.

Answer 1

a) When the displacement of a body is at right angle to the direction of force acting on it, then the work done will be zero. 

b) Force, F = 50N 

Distance, s = 4m 

Angle between direction of force and direction of motion, θ = 60 degree 

Work done, W = F cos θ s = 100 J